Trawling the research base for the

Crime Reduction online toolkit

CEPOL conference,

Tuesday 6th October 2015

Lisa Tompson, Jyoti Belur, Tanya Le Sage, Shane Johnson, Kate Bowers, Aiden

Sidebottom, Nick Tilley and Gloria Laycock

UCL Department of Security & Crime Science

Overview

• Systematically assembling the evidence base

• Where does the evidence come from?

• What do practitioners need from the evidence base?

• How fit for purpose is this evidence?

MISSION:

“to identify the best available evidence

on approaches to reducing crime

(and the potential savings to the police

service, their crime reduction partners

and the public)”

Structuring our research question

Findings from systematic

review or meta-analyses

Broadly defined ‘crime

prevention’

Overall aim was to search for evaluations of interventions in all relevant

fields that might have a crime prevention outcome

Final number of included studies = 328

Our systematic search flowchart

The crime prevention evidence base

• Commissioned by a variety of stakeholders who frame the research

question in many different ways

– By intervention

– By problem

– By population

– By context

– By policing strategy

– By outcome

– By stakeholder

• Implies that all these foci are relevant to practitioner sub-groups

Type of intervention

Timeline of evidence syntheses publication

What do practitioners need to know?

• Not just ‘what works’ – How it works (mechanism)

– Under what conditions it works (moderators)

– How to get it to work (implementation)

– How much it costs (economics)

• E.g. mandatory arrest of domestic violence offenders– Works for middle-class victims/offenders

– Doesn’t work for economically disadvantaged victims/offenders

?Inputs Outcome

EMMIE

Street lighting example

Making the evidence base accessible

How fit for purpose is the evidence?

• Most reviews don’t consider the active ingredients for why

an intervention might work

• The evidence is generally weak on effect, and often on

other dimensions– But need to remember that reviews rely on primary study evidence

• BUT, weak evidence on effect doesn’t undermine other

dimensions– I.e. reviews can be strong on moderators or implementation

Advancing the evidence base

• Need to encourage narrow systematic review topics– E.g. CBT for domestic violence offenders

– E.g. Property marking for reducing burglary

• Data collection in primary reviews should speak to the

aspects of an intervention that practitioners need to know– Moderator analysis is crucial in unpicking what may be effective for

different sub-groups

• Commissioners of primary research need to know this!

Thank you

Bowers, K., Tompson, L. & Johnson, S. (2014) Implementing information science in policing:

mapping the evidence base. Policing: A Journal of Policy and Practice.

Tompson, L. and Belur, J. (2015) Information retrieval in systematic reviews; A case study of

the crime prevention literature. Journal of Experimental Criminology.

Lisa Tompson

l.tompson@ucl.ac.uk